The present invention relates generally to agricultural implements and more specifically to a seeding implement having a frame supported by ground-engaging wheels and a material metering system driven by a ground-engaging wheel.
Seeding implements such as end-wheel drills are typically supported by a pair of ground-engaging wheels connected near the outer ends of a transversely extending frame. A plurality of ground-engaging tools are supported between the wheels for opening furrows in the ground and depositing granular material from a frame-mounted hopper through a metering system which is driven by a ground-engaging wheel. A lift mechanism is provided for raising and lowering the tools between field-working and transport positions. In some ground conditions, particularly in minimum tillage operations, the upward forces transmitted from the tools to the frame can actually lift the meter drive wheel causing skips in planting.
Many implements utilize an extra drive wheel to operate the metering device on the implement. This extra wheel adds to the expense of the implement and often requires a down-pressure spring to help maintain the wheel in good driving relationship with the soil. The additional wheel structure adds cost, weight and complexity to the implement. In addition, the meter drive wheel is often supported near the forward end of the implement by a forwardly extending arm which pushes rather than pulls the wheel and subjects the wheel structure to high stresses and wear.
In a seeding implement, such as a typical end-wheel drill wherein the wheels are mounted at the outermost ends of the frame, the increased width as a result of the outwardly mounted wheels can be detrimental to transport, especially over narrow roads and bridges and through narrow gates and the like. The end wheels also prevent planting of seeds close to the field edge.